Jacky Luiten

22 | Chapter 2 Table 2.3 Distribution of screen‐detected DCIS and invasive carcinomas by tumor grade. Year of screening 2005–2007 2007–2009 2009–2011 2011–2013 2013–2015 N (%) N (%) p value N (%) p value N (%) p value N % p value DCIS 0.131* 0.036* 0.013* 0.815* Low grade 8 (12.3) 9 (16.1) 48 (30.6) 33 (18.2) 26 (15.8) Intermediate grade 11 (16.9) 17 (30.4) 53 (33.8) 60 (33.1) 58 (35.7) High grade 46 (70.8) 30 (53.8) 56 (35.7) 88 (48.6) 80 (48.8) Invasive carcinoma 0.126* 0.003* 0.014* 0.240* Low grade 131 (50.0) 114 (41.3) 263 (50.1) 281 (45.4) 317 (41.4) Intermediate grade 89 (34.0) 117 (42.4) 213 (41.0) 250 (40.5) 344 (45.2) High grade 33 (12.6) 39 (14.1) 39 (7.5) 74 (12.0) 90 (11.8) Unknown 9 (3.4) 6 (2.2) 4 (0.8) 13 (2.1) 10 (1.3) * χ 2 test in comparison to previous screening cohort; ^ rate per 1000 women screened.